Bookbinding

ABSTRACT

A method for the conversion of strips of zigzag wire into a tubular form suitable for binding perforated sheets, comprising feeding the strip over an anvil in a step-by-step fashion, and clamping the strip whilst it is stationary so that the edges can be bent over the anvil by strikers situated on either side of the anvil.

United States Patent Sidney George William Adams Hersham, England Dec.6, 1968 Mar. 2, 1971 James Burn & Co. Ltd. Surrey, England Dec. 15, 1967Great Britain Inventor App]. N 0. Filed Patented Assignee PriorityBOOKBINDING 13 Claims, 12 Drawing Figs.

U.S. Cl 140/71, 140/82, 72/191 Int. Cl B211 45/00 Field of Search140/71, 82; 11/l;72/187, 191

[56] References Cited UNITED STATES PATENTS 2,190,722 2/1940 Martin140/82 2,832,392 4/1958 Spitz 140/71 2,868,236 1/1959 Smith 140/712,874,731 2/1959 Smith 140/71 3,451,081 6/1969 Liouville 1 l/ 1 PrimaryExaminer-Lowell A. Larson Attorney-Dowell & Dowell ABSTRACT: A methodfor the conversion of strips of zigzag wire into a tubular form suitablefor binding perforated sheets, comprising feeding the strip over ananvil in a step-by-step fashion, and clamping the strip whilst it isstationary so that the edges can be bent over the anvil by strikerssituated on either side of the anvil.

PATENTED HAR 219m SHEET 1 OF 6 MW M3321,

PATENTED m 2|9n SHEET 2 OF 6 lnve l r PATENTED MAR 2 [WI I SHEET *4 OF 6PATENTED HAR 2m: 3566;927

SJM B 0 WW PATENTEDHAR 21971 3566927 SHEET 6 BF 6 BOOKBINDING its wallthe final step in the binding process is to close the slot by briningthe closed ends of the prongs into their open ends.

The invention is concerned with the manufacture of the binding elementsin the form in which they exist at the binding or sheet impaling stage,i.e., in the slotted tube form.

In the manufacture of such elements, it is usual for a length of wirefirst of all t be converted to the so-called zigzag form in which itassumes the shape of a flat comb of indefinite length the prongs ofwhich are closed at their tips and open at their bases ro roots wherethey are connected to their neighbors by aligned lengths of wire formingthe stock or spine of the comb so that the pitch of the prongscorresponds to the pitch of the perforations in the sheetsjto be bound.A long length of such flat zigzag material is then brought to theslotted tube form by suitable bending of'the prongs.

The closed ends of the prongs will be referred to herein as the *tips"of the prongs and the lengths of wire separating successive prongs willbe referred to as the roots" of the prongs.

According to the invention, the conversion from the zigzag to theslotted tube condition is effected by feeding the wire over an anvil ina step-by-step fashion, and, while the strip is held stationary,clamping it so that the tips and roots of the prongs overhang the anvilstriking the overhanging portion of each prong to cause it to conform toa shape determined by I the anvil.

The bending can be effected in a single stage by using one striker, orin several stages, which is preferred, by using a number of strikers orhammers. In the latter case, the first striker bends the prongs neartheir ends and the second at a point closer to the clamp and so on.

The intermittent feed can be effected in various ways as, for example,by means of a ratchet mechanism or other mechanism having areciprocating or oscillating motion. It is, however, much preferable touse for the feeding of the strip a continuously rotated mechanism and,in particular, a rotary indexing wheel having a helical groove or scrollin which the tips and roots of the prongs are engaged and which hasstraight" portions, i.e., portions lying in planes at right angles tothe axis of the wheel which maintain the strip at rest at the instant atwhich a prong is to be acted on by a hammer or hammers, the later beingcarried by the wheel.

The final bending operation to close the binder after the sheets to bebound have been impaled on its prongs if facilitated if the prongs areprovided midway along their length with a kink which acts as a hinge.Such a kink can very conveniently be provided as a result of theclamping of the teeth of the zigzag strip while these are being shapedor formed by the strikers or hammers.

The invention will now be explained in greater detail with reference tothe accompanying drawings which are given by way of example.

FIG. 1 shows a length of zigzag strips;

FIG. 2 shows a length of the slotted tube;

FIG. 3 is a plan view of a machine in accordance with the invention;

FIG. 4 is a side elevation of the machine shown in FIG. 3;

FIG 5 shows one convolution of a scroll of the machine of FIG. 3;

FIGS. 6 to 9 are sections taken through FIG. 3 at VI to IX respectivelyand show the steps of converting the zigzag strip to a slotted tubularform; and

FIGS. 6A, 6B, and 6C show three examples of hammers or strikers whichcan be used.

The strip 10 shown in FIG. 1 is comblike, having prongs 14 closed attheir tips 16 and open at their roots 18 where they are connected bylengths of wire 20. In the condition of use illustrated in FIG. 2, theprongs 10 have been curved so that perforated sheets can be impaled.That operation having been performed, the binding completed by bringingthe tips 16 of the prongs into their roots or open ends 18, which isfacilitated by a kink 24 in each prong.

Referring to FIGS. 3 onwards the machine has a feed table 26 on whichthe zigzag strip 10 is longitudinally fed. It is thus presented to apair of stepped rollers 28, 30.

As will be seen, the stepped roller 28 is provided with a helical grooveor scroll 32 the pitch of which is that of the prongs of the zigzagstrip and the width of which is the dimension P in FIG. 1.

The stepped roller 30 has a similar groove or scroll 34 of the samepitch but of opposite hand and the width of which is that of a tip ofthe prong 12 of the zigzag strip.

It will be clear that rotation of the cylinders in opposite directionswith the zigzag'strip engaged in their grooves will result inlongitudinal movement of the strip over the table 26.

FIG. 5 of the drawings shows one convolution the scroll from which itwill be seen that over a sector S which is about one tenth of a circle,the groove is straight, .i.e., lies in a plane at right angles to theaxis of the cylinder. When the zigzag strip is engaged in that part ofthe grooves, its progression along the table 26 is arrested.'lt is atthis moment that the shaping of a prong is effected or started.

The table shown in FIG. 3 has a right-hand extension 36 the width of thetop of which decreases away from the table. When a tooth of zigzagpasses from the table 26 proper, as it is about to do as shown at 10AFIG. 6, its ends project beyond the side edges of the extension and liein the grooves 32 and 34 of the scrolls.

In the portion S of the first convolution of those grooves there is astriker or hammer 38 which strikes those ends and bends them into theposition shown at 108 in FIG. 7, the extension 36 of the feed tableacting as an anvil. In a further convolution, there is a further hammer39 at a greater radial distance from the axis of the cylinder which, oncontinued rotation of the latter, causes the partially bent zigzag to'be further bent into the position shown at 10C in FIG. 8. The; finaltubular form 10D is achieved by a third hammer 40 (FIG. 8).

There is, of course,,the possibility that the teeth of the zigzag stripafter passing beyond a hammer will tend to spring back. This may make itdesirable to duplicate the hammers in neighboring convolutions and fortheprongs to be bent by them beyond the finally desired position intowhich they spring back under the effect of their resilience.

It is important that the zigzag strip be accurately aligned along thefeed table when it reaches the feed cylinders. To that end a guide 50 isprovided as shown in FIG. 3.

In addition a platform or cam surface 52 (FIG. 6) is provided in eachgroove of the scrolls in a position so that it engages the outermostpart of each prong immediately before it isolamped. As the hammers 38are positioned on the rollers 28, 30 so as to strike the tips 16 and theroots of the prongs simultaneously, the platforms on opposing rollersengage the wire simultaneously. The platforms 52, whilst they areadjusted to the exact width of the wire at the respective stage, causethe strip to be positioned central on the anvil 26.

Also to enable the hammers 38, 39, 40 to do their work the central partsof the prongs, are held by a clamp shown at 44 in FIG. 3 which is causedat appropriate times to grip the strip between itself and the anvil 36after it has been positioned centrally by the platforms 52.

The clamp 44 is pivotally mounted at 60 and moved into its clampingposition by an eccentric 62 geared to the rollers 28, 30. A cam followerlever 63 which acts on an adjustable stop 64 at the free end of theclamp is urged into engagement with the eccentric by means of a spring65.

The clamp 44 has a projection 46 (FIG. 9) which serves at the same timeto put into the prongs of the binder the kinks referred to above inconnection with FIG. 2, the anvil 36 having depression 47 matching theprojection 46. Thus, the flat zigzag is converted to the slotted tubeshape of FIG. 2 and is indexed along the feed table by a mechanism whichis exclusively rotary.

The shape and constitution of the hammers can be varied within widelimits. It is advantageous for them to exert a gradually increasingpressure on the parts they are designed to bend. They can, for example,be formed as rollers or they can be fixed cam surfaces any desiredshape. Being subject to wear they should be made of a hardened materialand mounted for easy removal and replacement. Some examples of hammersare shown in FIGS. 6A, 6B, and 6C. At A therein, the hammer is ahardened steel insert in a slot 66 in which it is held by a screw 68 atany desired projection. At B, the hammer is a cam or eccentric the throwof which is adjustable by rotation. At C, the hammer is a spring-pressedroller which can yield to a limited extend as it passes the tooth of thezigzag to be bent.

In FIG. 3, the scrolls are shown as single-start helical grooves. Theycould be formed as mutiple start grooves.

An advantage'of the machine is that it can be very conveniently made tofollow a zigzag forming machine and particularly one in which thezigzags are formed by rotary member such, for example, as that formingthe subject of Pat. No. 939,649. As the machine of the present inventionhas a rotary drive, its input shaft can be coupled to a shaft of thezigzag machine so that the two machines are perfectly synchronized andcannot get out of step.

Where the machine is fitted following a zigzag forming machine, somelengthwise adjustment of the rollers 28, 30 may be necessary to preventa bunching-up or snaking of the wire. This is achieved by turningscrew-threaded locking washers 56 on the drive shafts 58 of the rollers.

Although a purely rotary drive is advantageous, it is not essential.

We claim:

1. Apparatus for converting strips of zigzagged wire to be slottedtubular form as set forth herein, comprising means for feeding the striplongitudinally, means for momentarily arresting the feed of each prongas it reaches a shaping station, means for clamping each prong at thatstation with its tip and root overhanging an anvil on which it rests andmeans at the shaping station arranged to strike the overhanging portionsof a clamped prong to cause them to conform to a shape determined by theanvil, said means comprising a pair of rotors disposed with their axesparallel to the longitudinal axis of the strip and strikers whichproject radially from said rotors so that the parts of the prongs whichoverhand the anvil lie in the path of the strikes so as to be struck bythem in passing.

2. Apparatus according to claim 1 in which the said rotors have helicalscrolls in which the tips and roots engage so as to constitute the stripfeeding means.

3. Apparatus according to claim 2 in which each scroll has a portionlying in a plane at right angles to its axis and serving to arrest thefeed of each prong momentarily while it is being shaped.

4. Apparatus according to claim 1 in which the strikers are housed inthe grooves of the scrolls.

5. Apparatus according to claim 1 having a number of strikers at theshaping station arranged one after the other in the direction ofmovement of the strip at progressively decreasing distances from thecenterline of the strip.

6. Apparatus according to claim 1 in which means are provided at theshaping station for centering the strip immediately before it isclamped.

7. Apparatus according to claim 6 in which the said means are in theform of cam surfaces on the helically grooved rollers.

8. Apparatus according to claim 7 in which the clamping means also serveto indent that part of each prong which is midway between its tip andits root.

9. Apparatus for converting strips of zigzagged wire to the slottedtubular form as set forth herein, comprising means for feeding striplongitudinally to and through a shaping station,

an anvil at said shaping station adapted to support said strip with thetip and root of each prong laterally overhanging it and means disposedlaterally of said anvil on each side thereof for rotation about an axisparallel to the longitudinal axis of the strip and having radialprojection adapted on rotation of said means to strike and overhangingtips and roots in passing.

10. Apparatus according to claim 9 wh in which the extremities of saidprojections are rounded whereby to ensure substantially rolling actionbetween them and the tips and roots of the prongs.

11. Apparatus according to claim 9 in which said rotary means arerollers and are formed with radial housings for said projections and inwhich means are provided for radial adjustment of the projections in thehousing and for fixing them in any adjusted position.

12. Apparatus according to claim 9 which said feeding means compriserollers formed with helical grooves in which the tips and prongs of thezigzag strip engage.

13. Apparatus as claimed in claim 9 in which said feeding means comprisea pair of rollers formed with helical grooves in which the tips andprongs of the zigzag strip engage and in which said rotary means areextensions of said rollers.

1. Apparatus for converting strips of zigzagged wire to be slottedtubular form as set forth herein, comprising means for feeding the striplongitudinally, means for momentarily arresting the feed of each prongas it reaches a shaping station, means for clamping each prong at thatstation with its tip and root overhanging an anvil on which it rests andmeans at the shaping station arranged to strike the overhanging portionsof a clamped prong to cause them to conform to a shape determined by theanvil, said means comprising a pair of rotors disposed with their axesparallel to the longitudinal axis of the strip and strikers whichproject radially from said rotors so that the parts of the prongs whichoverhand the anvil lie in the path of the strikes so as to be stRuck bythem in passing.
 2. Apparatus according to claim 1 in which the saidrotors have helical scrolls in which the tips and roots engage so as toconstitute the strip feeding means.
 3. Apparatus according to claim 2 inwhich each scroll has a portion lying in a plane at right angles to itsaxis and serving to arrest the feed of each prong momentarily while itis being shaped.
 4. Apparatus according to claim 1 in which the strikersare housed in the grooves of the scrolls.
 5. Apparatus according toclaim 1 having a number of strikers at the shaping station arranged oneafter the other in the direction of movement of the strip atprogressively decreasing distances from the centerline of the strip. 6.Apparatus according to claim 1 in which means are provided at theshaping station for centering the strip immediately before it isclamped.
 7. Apparatus according to claim 6 in which the said means arein the form of cam surfaces on the helically grooved rollers. 8.Apparatus according to claim 7 in which the clamping means also serve toindent that part of each prong which is midway between its tip and itsroot.
 9. Apparatus for converting strips of zigzagged wire to theslotted tubular form as set forth herein, comprising means for feedingstrip longitudinally to and through a shaping station, an anvil at saidshaping station adapted to support said strip with the tip and root ofeach prong laterally overhanging it and means disposed laterally of saidanvil on each side thereof for rotation about an axis parallel to thelongitudinal axis of the strip and having radial projection adapted onrotation of said means to strike and overhanging tips and roots inpassing.
 10. Apparatus according to claim 9 wh in which the extremitiesof said projections are rounded whereby to ensure substantially rollingaction between them and the tips and roots of the prongs.
 11. Apparatusaccording to claim 9 in which said rotary means are rollers and areformed with radial housings for said projections and in which means areprovided for radial adjustment of the projections in the housing and forfixing them in any adjusted position.
 12. Apparatus according to claim 9which said feeding means comprise rollers formed with helical grooves inwhich the tips and prongs of the zigzag strip engage.
 13. Apparatus asclaimed in claim 9 in which said feeding means comprise a pair ofrollers formed with helical grooves in which the tips and prongs of thezigzag strip engage and in which said rotary means are extensions ofsaid rollers.